High molecular weight water soluble polymers such as polyethylene oxide (PEO), polyacrylamide (PAM) and partially hydrolyzed polyacrylamide (HPAM) have been demonstrated to reduce drag in turbulent flows of aqueous liquids.
The instant invention discloses new efficient drag reduction agents in aqueous liquids which are a novel class of acrylamide copolymers containing nonionic surfactant monomers.
Polymerizable esters of acrylic acid or methacrylic acid with alkyl or alkylaryl poly(ethyleneoxy)ethyl alcohols are disclosed in Dickstein U.S. Pat. No. 4,075,411, ##STR1## Trecker, U.S. Pat. No. 3,896,161 and British Pat. No. 828,496. Such monomers have found use in the preparation of stable latexes and special textiles.
Copolymers of base-neutralized acrylic acid and nonionic surfactant acrylates have also found use as thickeners for both aqueous solutions and water/organic liquid emulsions (Koenig and Bryant, U.S. Pat. No. 4,268,641). Improved NaCl tolerance is also taught therein. A liquid composition useful as a thickening agent in polymer latexes, comprising a mixture of solvent and a terpolymer of acrylic acid, an ester of the formula of ##STR2## and an alkyl acrylate or methacrylate is claimed in U.S. Pat. No. 4,138,381.